zombie84 said:

It's in The Making of ROTS, along with a synopsis of the rough draft he is in, bringing Yoda intel about the location of Grievous.

I totally forgot about how Kid Solo almost made his way in there to join Kid Boba and Kid Vader. Wow. I wonder who talked George out of that "awesome storyline."

And aside from Lucas finally getting to show the Wookiee planet of Kashyyyk, there's really no point of having Chewbacca in the movie aside from giving the audience that little wink. Obi-Wan is never there to make that little connection to seeing him in the Mos Eisley cantina, so who cares.